There are several patents which disclose the preparation of water-based sulfonated polymer compositions:
U.S. Pat. No. 5,334,690 (Hoechst Aktiengesellschaft) discloses water-based sulfonated polyurethane-urea polymers which can be combined with and are in general compatible with other aqueous polymer dispersions.
U.S. Pat. No. 4,888,383 (E. I. DuPont De Nemours and Company) discloses a process wherein water-based polyurethane-urea modified acrylic polymers are prepared by reacting amine and/or hydrazide functional polyacrylic polymers with isocyanate terminated polyurethane prepolymers.
U.S. Pat. No. 4,491,646 (Ashland) discloses adhesives wherein hydroxyl functional polyvinyl polymers are blended with water dispersible polyfunctional isocyanates.
Other related patents include U.S. Pat. No. 5,371,133 (National Starch), U.S. Pat. No. 5,200,463 (Huels), U.S. Pat. No. 5,204,404 (DuPont), U.S. Pat. No. 5,173,526 (Air Products & Chemicals, Inc.) and U.S. Pat. No. 5,071,904 (PPG).